Bosch, the world's biggest auto parts supplier, said on Thursday that the roughly 46 million shares it held in Denso, the second-biggest parts maker, since the mid-1950s were considered to be only a financial investment and that they were sold in recent days.

Denso spokesman Shuji Kojima said there will be no changes in existing technological and business tie-ups between the two auto parts makers.

"We will continue to seek further cooperation within our existing tie-up framework," he said.

Bosch and Denso, while competitors, have license agreements under which they share certain powertrain-related technologies.

They also have a joint venture in the United States that manufactures fuel pump parts, and another one in Japan that produces car navigation systems.